Time dispersion compensating device applied to the generation of ultra-short light pulses

Abstract

A device for compensating time dispersions applied to the generation of ultra-short pulses, includes: two transparent optical diffraction gratings (RA, RB), which are identical and parallel to each other, operating on the principle of the Bragg diffraction, and two identical prisms (PA, PB), placed head to tail, in the space separating the optical diffraction gratings (RA, RB), knowing that the outer faces (FeA, FeB) of the prisms are parallel to each other and form a non-zero angle (γ) with the faces of the optical diffraction gratings.

1 . A device for compensating time dispersions applied to the generation of ultra-short pulses with optic frequency (ν), comprising:
 two transparent optical diffraction gratings (RA, RB), which are identical and parallel to each other, operating on the principle of the Bragg diffraction, and 
 two identical prisms (PA, PB), placed head to tail, in the space separating said aforementioned optical diffraction gratings (RA, RB), 
 
       characterized in that the outer faces (FeA, FeB) of said aforementioned prisms (PA, PB) are parallel to each other and form a non-zero angle (γ) with the faces of said aforementioned optical diffraction gratings (RA, RB). 
     
     
         2 . The device according to  claim 1 , characterized in that it introduces a group delay time (t g ) whereof the variation as a function of the optical frequency (ν) compensates the variation of a group delay time (t R ) introduced by one or the group of the elements of an optical channel up to the 4 th  order of the Taylor series of said delay time (t R ). 
     
     
         3 . A time dispersion compensating device, characterized in that it comprises a first device according to  claim 2  and a second device, the second device being oriented at 180° relative to the first device. 
     
     
         4 . A method for compressing laser pulses previously stretched by a dispersive optical device, characterized in that it uses a device according to  claim 1 . 
     
     
         5 . A method for compensating the time dispersion of an acousto-optic filter, which may or may not be programmable, characterized in that it illustrates a device according to  claim 1 . 
     
     
         6 . A method for compressing laser pulses previously stretched by a dispersive optical device, characterized in that it uses a device according to  claim 2 . 
     
     
         7 . A method for compressing laser pulses previously stretched by a dispersive optical device, characterized in that it uses a device according to  claim 3 . 
     
     
         8 . A method for compensating the time dispersion of an acousto-optic filter, which may or may not be programmable, characterized in that it illustrates a device according to  claim 2 . 
     
     
         9 . A method for compensating the time dispersion of an acousto-optic filter, which may or may not be programmable, characterized in that it illustrates a device according to  claim 3 .